This invention relates to dispensing closures for liquid products held in containers, particularly squeezable plastic bottles. The closure will usually have a hinged cover, although this is not essential to the present invention.
In the dispensing of some products from squeezable bottles, in particular tomato ketchups, difficulties arise with separation of the product into separate parts of respective lighter and heavier consistencies, and a tendency for the lighter consistency part to collect at the top of the product as a discrete layer.
With a tomato ketchup the lighter consistency part is a clear but red-tinted liquid known as xe2x80x9cserumxe2x80x9d, and problems may arise when the user inverts the bottle prior to squeezing it for dispensing. Being of a relatively non-viscous nature, serum tends to spurt or drip from the closure before the more viscous ketchup can reach the dispensing aperture and close it off against further escape of product. To the consumer this premature escape of serum has been messy and annoying, with the result that the appeal of the ketchup as a consumer product has been reduced.
One object of the present invention is therefore to provide a closure capable of dispensing separating products such as tomato ketchup in a way which reduces or obviates any tendency for the lighter fraction of the product to leak from the closure prior to a normal dispensing operation.
In order to hermetically seal a bottle it is known to use a disc of plastics, paper and/or metal foil which is peripherally bonded, especially by heat or electrical induction, to the bottle neck rim to form a plane diaphragm closing the bottle mouth. The bond strength between the diaphragm and the bottle may then be such that it can be peeled away by the user after removal of the closure; alternatively the diaphragm may be permanently attached to the bottle and required to be pierced before product can be dispensed. The present invention relates to a closure for a container of the latter kind, that is to say, having its mouth closed by a piercable diaphragm.
Two earlier proposals for dispensers closures capable of piercing diaphragm closures on bottle mouths are described in EP 0296100 and EP 0473678. However, in each of these proposals the member which pierces the diaphragm to create the dispensing aperture is incapable of plugging the dispensing aperture, either because it is shaped to provide a free path for product flow, or because it is withdrawn resiliently from the diaphragm following the piercing operation. With each of these prior proposals there is therefore a danger that tomato ketchup serum will escape prior to dispensing.
GB 1152931 describes a closure with a piercing member which pierces a diaphragm and plugs the dispensing aperture. However, the member is completely removed from the aperture together with the rest of the closure before product can escape from the unplugged aperture.
In accordance with the invention from a first aspect there is provided a dispensing closure for a liquid product container having an opening closed by a piercable diaphragm, the closure having a piercing member with a cutting edge, which is moveable through a predetermined distance and is adapted to pierce the diaphragm during such movement to form a severed edge which defines a dispensing aperture, at the end of its movement the piercing member is arranged to plug the dispensing aperture against escape of product, characterised in that, at the end of its movement the piercing member is maintained in contact with the severed edge to plug the dispensing aperture, and in that when the container is inverted the piercing member is held in its depressed position, product may be subsequently dispensed from the container through the dispensing aperture by generating an increased product pressure in the container, which lifts the severed edge away from at least part of the piercing member, thereby opening the dispensing aperture.
According to a preferred feature of the invention the movable member is located and movable within a dispensing spout or nozzle by which product being dispensed may leave the closure. Desirably the spout and movable member are laterally offset in relation to the closure, so that they can be located adjacent the bottom of the closure when the associated container is downwardly tilted for dispensing.
In order that the invention may be more fully understood embodiments thereof will now be described, by way of example only and with reference to the accompanying drawings. In the drawings: